Johannes married Susanna Wahl on 6 Jul 1761 in Niederschlettenbach, Pfalz. Susanna (daughter of Johannes Philipp Wahl and Katharina Zeholtz) was born on 26 Feb 1736 in Erlenbach bei Dahn, Pfalz; was christened on 26 Feb 1736 in Erlenbach bei Dahn, Pfalz; died on 10 Apr 1766 in Niederschlettenbach, Pfalz. [Group Sheet] [Family Chart]

Johannes married Anna Maria Schäffer on 2 Mar 1767 in Niederschlettenbach, Pfalz. Anna (daughter of Johannes Schäffer and Maria Magdalena Schumacher) was born in 1746 in Wissembourg, Bas-Rhin, Alsace, France; died on 20 Dec 1777 in Niederschlettenbach, Pfalz, Bayern. [Group Sheet] [Family Chart]

1. Maria Ottilia Mertz was born on 19 Feb 1771 in Niederschlettenbach, Pfalz.

Johannes married Maria Elisabetha Jüllich on 15 May 1778 in Niederschlettenbach, Pfalz. Maria (daughter of Johannes Peter Jüllich and Maria Elisabetha Salzmann) was born on 14 Sep 1753 in Vollmersweiler, Pfalz; was christened on 16 Sep 1753 in Freckenfeld, Pfalz. [Group Sheet] [Family Chart]

1. Joseph Mertz was born on 27 Jun 1780 in Niederschlettenbach, Pfalz; died on 9 Dec 1837 in Niederschlettenbach, Pfalz, Bayern.
2. Johannes Mertz was born on 7 Aug 1782 in Niederschlettenbach, Pfalz; died on 28 Apr 1788 in Niederschlettenbach, Pfalz.
3. Lorenz Mertz was born on 29 Jan 1785 in Niederschlettenbach, Pfalz; died on 3 Feb 1785 in Niederschlettenbach, Pfalz.
4. Margaretha Mertz was born on 8 Feb 1786 in Niederschlettenbach, Pfalz; died on 23 Mar 1789 in Niederschlettenbach, Pfalz.
5. Maria Anna Mertz was born on 5 Sep 1788 in Niederschlettenbach, Pfalz.
6. Johannes Mertz was born on 31 Oct 1790 in Niederschlettenbach, Pfalz; died on 18 May 1794 in Niederschlettenbach, Pfalz.

Martin married Maria Margaretha Helfer. Maria was born in 1700 in Niederschlettenbach, Pfalz; died on 31 Dec 1763 in Niederschlettenbach, Pfalz. [Group Sheet] [Family Chart]